[rrd-users] 95th Percentile calculation

[William Pitcock]

Hi,

I am entirely stumped on how to calculate and graph 95th percentile
usage using the VDEF function in rrdtool 1.2 or greater.

My configuration is like this:

DEF:inoctets=rrdfile.rrd:inoctets:LAST
DEF:outoctets=rrdfile.rrd:outoctets:LAST
CDEF:inbits=inoctets,8,*
CDEF:outbits=outoctets,8,*
CDEF:allbits=inbits,outbits,+
VDEF:95th=allbits,95,PERCENT
AREA:inbits#00FF00:In
LINE:outbits#OOOOFF:Out
HRULE:95th#FF0000:95th
GPRINT:95th:"%6.2lf %Sbps"

Unfortunately Cacti, for example, precalculates this value and plots
it. :(

William